The present invention relates to water pressure systems for water wells, and more particularly, to a pressure tank installed underground in the well casing of a well, and used in combination with a flow control valve or a variable speed pump in a water pressure system.
A typical water pressure system for a home is established by first drilling a hole in the ground in search of water from a water bearing aquifer. Once water is reached by the drill, a well casing is inserted into the bore hole to preserve the sides of the well. A submersible pump is then inserted into the well below the water level to pump water from the aquifer. One end of a drop pipe is attached to the submersible pump to draw water out of the well. The other end of the drop pipe is attached to a pitless adapter, which is attached to a discharge pipe for carrying water to a pressure tank located in the house or in another building next to the house. Water from the pressure tank is then distributed throughout the house for use.
The pressure tank holds a reserve supply of water under pressure within the tank. A pressure switch coupled to the tank is used to maintain water pressure in tank between a minimum value and a maximum value. The pressure switch activates the submersible pump to pump water into the tank when the water pressure in the tank drops below to the minimum value. Water is then pumped into the tank to replenish the tank with water and to build up the pressure in the tank to its maximum value. Once the pressure in the tank has reached its maximum value, the pressure switch stops the pump from operating. The switch activates the pump generally whenever water is drawn from the tank. The water is stored in the tank under pressure until it""s needed. As water is drawn from the tank, the pressure in the tank decreases. Upon reaching the set minimum pressure, the pressure switch automatically activates the pump.
Pressure tanks are normally of substantial size, and consequently are limited to above ground installations in water pressure systems. Typically, pressure tanks are installed in the basement of a house or in a separate building near the house to protect it from the elements. This is especially true in cold climates. Adverse weather conditions can effect the reliability of a pressure tank in cold weather. During the winter months, the pressure tanks must be protected from the cold and snow. Therefore, the tanks are either installed in a basement or in an insulated building above ground.
However, there are problems associated with above ground installations of pressure tanks. A problem with installing a tank in the basement of a building is that the tank may take up valuable space in the home. Also, the installation of the pressure tank can be quite difficult and time-consuming. In addition, the installation of a pressure tank above ground in cold weather climates may require the tank be installed in a separate insulated building. And the tank must often be wrapped in insulation and heat tape.
Water pressure tanks installed underground are known in the art. For example U.S. Pat. No. 3,394,733 to Jacuzzi discloses an airless water pressure system utilizing an underground pressure tank. The pressure tank of this invention includes an expansible tube installed around a pipe having openings therein to transfer liquid from the pipe to the expansible tube. The tube is clamped at each end to allow the liquid under pressure to cause expansion of the tube. However, the clamped ends of the tube have been known to fail under pressure from the liquid. In another patent to Jacuzzi, U.S. Pat. No. 3,442,292 discloses a pressure tank installed underground in a well, having water flowing into the pressure tank around an air filled bladder. The problem with this patented invention is that the air filled bladder seals off water flow from the inlet end of the tank to the outlet end of the tank. In other words, water freely flows into the tank but is sealed off from exiting the tank by the air filled bladder pressing against the walls of the tank.
Accordingly, there is a need for a water pressure system that allows for installation of a pressure tank underground in the well casing of a water well, that is more reliable in cold weather, less expensive to install, and more easily maintained than prior art systems.
The present invention is a new arrangement for a well pressure tank used in water pressure systems utilizing water wells. In most existing home water pressure systems, the pressure tank is located either in the home or in a separate building near the home. The pressure tank of the present invention is designed to be located in the well casing of a water well. A typical well casing is approximately six inches in diameter. The tank of the present invention is approximately four inches in diameter and approximately ten feet long. The tank has a draw down capacity of approximately 1-3 gallons of water. The pressure tank of the present invention is reduced in size, more reliable in cold weather, less expensive to install, and more easily maintained than prior art pressure tanks.
The water pressure system of the present invention pumps water from a water bearing aquifer to a pressure tank installed underground in the well casing of a well. The water pressure system includes a submersible pump inserted in the well below the water level to pump water from the aquifer. One end of a first drop pipe is attached to the submersible pump, while the other end of the first drop pipe is attached to an inlet opening in a pressure tank installed in the well casing of the well. Water flows from the submersible pump through the drop pipe and into the pressure tank. The water enters the pressure tank through the inlet opening, and is either stored in the tank for future use, or continues to flow out through an outlet opening in the tank. One end of a second drop pipe is connected to the outlet opening in the tank. The other end of the second drop pipe is attached to a pitless adapter which is connected to a discharge pipe for carrying pressurized water to a house or other building for use.
The pressure tank includes a main body having an inlet end, an outlet end, and an outer sidewall. Attached to the inlet end of the tank are an inlet end cap and an inlet plug. The inlet plug is inserted within the inlet end cap. An expandable diaphragm bladder is connected between the inlet plug and the outlet end cap. A tube extends through the center of the expandable diaphragm bladder between an inlet opening and an outlet opening. The tube has a plurality of holes therein to allow water to flow through the tube and into and out of the expandable bladder. The inlet opening of the diaphragm bladder is clamped to a ribbed end of the inlet plug with a clamping device. The outlet opening of the diaphragm bladder is clamped to a ribbed end of the outlet end cap with a similar clamping device. Pressurized air fills the empty space between the bladder and the outer sidewall of the tank to pressurize the water in the expandable bladder.
The outlet end of the drop pipe opposite the end connected to the submersible pump is connected to the inlet plug extending through the inlet end cap of the pressure tank. The other end of the inlet plug is connected to the inlet end of the diaphragm bladder. The outlet end of the diaphragm bladder is attached to the outlet end cap. Water flows through the openings in the inlet end cap, inlet plug, diaphragm bladder, and outlet end cap to a second drop pipe connected to the outlet end cap of the tank. The other end of the second drop pipe is connected to a pitless adapter, which in turn is connected to a discharge pipe for carrying water to the home.
A pressure switch coupled to the pressure tank regulates water pressure in the pressure tank by maintaining the water pressure between a minimum value and a maximum value. The pressure switch continuously monitors the water pressure in the tank, and controls the submersible pump accordingly. The pressure switch responds to a drop in pressure below the minimum value by starting the pump to replenish the water in the tank and to build up the water pressure to its maximum value. The pressure switch stops the pump when the water pressure reaches the maximum value and restarts the pump when the pressure drops below the minimum value.
A first embodiment of the invention includes the well pressure tank used in combination with a flow control valve. The flow control valve automatically adjusts the submersible pump""s output to match the flow requirements of the user. The flow control valve maintains constant water pressure in the system. The flow control valve eliminates changes in water pressure and reduces the need for a large storage pressure tank.
A second embodiment of the invention includes the well pressure tank used in combination with a variable speed pump. The variable speed pump performs much the same function as the flow control valve, so that the flow control valve is no longer needed in the water pressure system to maintain constant water pressure. In this embodiment, constant water pressure is maintained by continuously adjusting pump speed to meet water demand. This type of system also minimizes pressure cycling during long-running applications, such as when someone is taking a shower.
Various other features, objects, and advantages of the invention will be made apparent to those skilled in the art from the following drawings and detailed description of the invention.